The microheterogeneity components of orosomucoid and the dissociation constants and mobilities of concanavalin A/corosomucoid complexes in crossed affinoimmunoelectrophoresis with free concanavalin A

In crossed affinoimmunoelectrophoresis with free concanavalin A (Con A) in the first dimension, four orosomucoid components are normally found in human serum. In this study an optimal range of Con A concentration in the first‐dimension gel was defined. The most retarded, fourth component of orosomucoid was shown to be a result of entrapment of Con A‐binding molecules in the affinity precipitate. The affinities of the second, weakly retarded, component and of the third, strongly retarded, component to a Con A binding site were found to be identical. The mobilities in the first‐dimension electrophoresis of the orosomucoid/Con A complexes were found to be significantly different from each other. Compared to the mobility of the nonretarded, first, component of orosomucoid, the second component had a mobility of 40% and the third component had a mobility of 10%. Differences in the antennary carbohydrate structures on the glycosylation sites of orosomucoid are suggested as an explanation for these observations.